Subway

Substrate JSON RPC Gateway.

This is a generalized JSON RPC proxy server with features specifically designed for Substrate RPC and Ethereum RPC.

Getting Started

Pull vendors: git submodule update --init --recursive

Quick start: cargo run -- --config config.yml

This will run a proxy server with config.yml as the configuration file.

Run with RUSTFLAGS="--cfg tokio_unstable" to enable tokio-console

Environment Variables

• RUST_LOG
  • Log level. Default: info.
• PORT
  • Override port configuration in config file.
• LOG_FORMAT
  • Log format. Default: full.
  • Options: full, pretty, json, compact

Features

Subway is build with middleware pattern.

Middlewares

Method Middlewares

• Cache
  • Cache responses from upstream middleware.
• Call
  • Forward requests to upstream servers.
• Inject Params (Substrate)
  • For Substrate RPC
  • Inject optional blockAt or blockHash params to requests to ensure downstream middleware such as cache can work properly.
• Inject Params (Ethereum)
  • For Ethereum RPC
  • Inject optional defaultBlock parameter to requests to ensure downstream middleware such as cache can work properly.
• Subscription
  • Forward requests to upstream servers.
  • TODO: Merge duplicated subscriptions.
• TODO: Rate Limit
  • Rate limit requests from downstream middleware.
• TODO: Parameter filter
  • Deny requests with invalid parameters.

Additional features

• Advance JSON RPC Client
  • Supports multiple upstream servers and rotate & reconnect on failure.
  • TODO: Load balance requests to upstream servers.
• Batch Request
  • TODO: Process requests individually so they can be cached properly by downstream middlewares.
  • TODO: Limit batch size, request size and response size.
• TODO: Metrics
  • Getting insights of the RPC calls and server performance.

Benchmarks

To run all benchmarks:

cargo bench

It's also possible to run individual benchmarks by:

cargo bench --bench bench ws_round_trip